P1246 编码

R52599287

Luogu/problem/P1246/P1246.cpp

@@ -0,0 +1,29 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int cnt = 0;
+map<string, int> m;
+string s1, s2;
+
+void dfs(int l, int k) {
+    if (k > l) {
+        m[s1] = ++cnt;
+        return;
+    }
+    for (char c = (k == 1 ? 'a' : s1[k - 2] + 1); c <= 'z'; c++) {
+        s1[k - 1] = c;
+        dfs(l, k + 1);
+    }
+}
+
+int main() {
+    for (int i = 1; i <= 6; i++) {
+        s1.clear();
+        s1.resize(i);
+        dfs(i, 1);
+    }
+    cin >> s2;
+    cout << m[s2] << endl;
+    return 0;
+}